Speedo Men's Endurance+ Polyester Solid Square Leg Swimsuit 50% Polyester/50% PBT Endurance+ is 100% chlorine resistant fabric designed to lasts 20 times longer than conventional swimwear fabrics Four-Way Stretch technology also provides a body-hugging fit, great shape retention and soft comfort UV Protection 50+. Front gusset Low moisture absorption and quick drying Inside drawstring at waist for secure fit